Assessing Genetic Variation among Strychnos spinosa Lam. Morphotypes Using Simple Sequence Repeat Markers.

Area of Science:

• * Botany
• * Genetics
• * Molecular Biology

Background:

• * Strychnos spinosa (green monkey orange) is a valuable indigenous South African fruit tree with domestication potential.
• * Limited molecular diversity data exists for Strychnos spinosa morphotypes.
• * Understanding genetic variation is crucial for conservation and crop improvement.

Purpose of the Study:

• * To determine the genetic variation among 32 Strychnos spinosa morphotypes.
• * To develop and utilize simple sequence repeat (SSR) markers for molecular characterization.
• * To investigate the population structure of Strychnos spinosa.

Main Methods:

• * Amplification of 14 simple sequence repeat (SSR) markers across 32 Strychnos spinosa morphotypes.
• * Analysis of allele number, polymorphic information content (PIC), and genetic distances.
• * Application of Bayesian inference for population structure analysis.

Main Results:

• * A total of 159 alleles were identified, with a mean of 5.68 per locus.
• * Polymorphic Information Content (PIC) values ranged from 0.22 to 0.84.
• * Morphotypes clustered based on genetic distances, primarily correlating with pericarp texture.
• * Three distinct subpopulations were identified using Bayesian analysis, aligning with genetic distances.

Conclusions:

• * This is the first study to report on SSR marker development and application for Strychnos spinosa genetic diversity and population structure.
• * Molecular characterization provides insights into the genetic landscape of Strychnos spinosa.
• * Findings support targeted breeding and crop improvement programs for Strychnos spinosa, potentially enhancing food security.